Writing-tablet



UNITED STATES PATENT OFFICE.

GEORGE MUNGER, OF NEW HAVEN, CONNECTICUT.

WRITING-TABLET.

Specification forming part of Letters Patent No. 25,576, dated September27, 1859.

To all whom it may concern:

Be it known that I, GEORGE MUNGER, of the city and county of New Haven,and State of Connecticut, have invented a new and useful article ofmanufacture-to wit, an argillaccous-surfaced Wood writing-slate; and 1do hereby declare that the following is a full, clear, and exactdescription of the same.

The nature of my invention consists in a new article of manufacturetowit, an argillaceous-surfaced wood writing-slatewhich is formed byuniting several layers of veneering or thin wood together, so that theirgrains run antagonistically to each other, and then coating the exteriorsurface of the compact mass with a composition of slate, emery, or othersimilarargillaceousmaterial. Thusconstructing artificial slates enablesme to furnish the market with a cheap article which cannot be broken bya fall, and which will present as good a surface for marking upon as themost finished solid argillaceous article, as it is not liable to crackor warp by expansion and contraction, the antagonistic run of the grainsof the several layers effectually preventing the same.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

Two or more thin layers of wood are attached to each othersuperficially, by glue or other adhesive substance, so as to form asingle compact plate composed of several distinct layers. These layersare to be adjusted in such a manner that the grain or fiber of the woodshall not be parallel in either of the adjacent plates. The object ofthis disposition is that the contraction or expansion of each of thelayers may reciprocally counteract that of the others by being in anopposite direction, and thus the plane surfaces of the combined platemay be preserved free from cracks or warps. The compact plate thusconstructed is covered with a composition of slate, emery, or othermaterials put on in a liquid state, and which, when dry and hardened,shall form a surface on which marks can be made by a slate or soapstonepencil,as on an ordinary slate.

What I claim as my invention, and desire to secure by Letters Patent,is-- A new article of manufacture-to wit, an argillaceous-surfaeed woodwriting-slate which is formed by uniting several layers of veneering orthin wood together, so that their grains run antagonistic to oneanother, and then coating the exterior surfaces of the compact mass witha composition of slate, emery, or other similar argillaceous material,substantially as and for the purposes set forth.

GEORGE MUNGER.

